tbuckley/cabot-search huggingface dataset:
TMET-03. REPROGRAMMING OF GLIOBLASTOMA GLUCOSE METABOLISM FUELS TUMOR GROWTH
Authors: Andrew J Scott, Anjali Mittal, Wajd Al-Holou, Sravya Palavalasa, Baharan Meghdadi, Alexandra O'Brien, Weihua Zhou, Annabel Yang, Zitong Zhao, Angelica Lin, Vijay Tarnal, Costas Lyssiotis, Deepak Nagrath, Daniel R Wahl
Journal: Neuro-Oncology (2023)

Abstract Metabolic adaptation can promote oncogenic phenotypes in glioblastoma (GBM), but the metabolic pathways utilized by GBM and how they differ from the pathways utilized in normal cortex are poorly understood. Here, we utilize in vivo stable isotope tracing in mice and patients with GBM to define carbon fate and metabolic rewiring in cancer. We infused uniformly-labeled 13C glucose into mice bearing orthotopic GBM patient-derived xenografts or into patients undergoing surgical resection for likely GBM. Tumor and cortex were physically separated in mice by fluorescence-guided microdissection. In humans, samples of enhancing tumor, non-enhancing tumor and normal cortex were separated intraoperatively using MRI guidance. Samples were subsequently analyzed by liquid chromatography mass spectrometry to determine the downstream metabolic fates of infused 13C glucose. Of eight patients infused with 13C6-glucose, six were confirmed to have GBM while the others had non-GBM high grade gliomas. In mice and in patients, glucose-derived carbon effectively entered glycolysis and labeled glycolytic intermediates equivalently in tumor and cortex. Compared to GBM tissue, cortical tissue preferentially oxidized glucose-derived carbon in the TCA cycle and used glucose-derived carbon to synthesize neurotransmitters. Cortical tissue utilized glucose-derived carbon to synthesize the amino acid and neurotransmitter precursor serine, while GBM tissue derived serine from extracellular sources. By contrast, GBM tissue preferentially utilized glucose-derived carbon for the synthesis of purines, pyrimidines and NAD+/NADH. Using time-course isotope tracing studies in mice with GBM and a novel metabolic flux analysis framework, we quantified absolute metabolic fluxes in vivo and confirmed elevated nucleotide synthesis and serine salvage in GBM. Consistent with these results, eliminating dietary serine in mice slowed GBM PDX growth. These studies are the first measurements of numerous metabolic pathways in humans and indicate that GBMs suppress the physiologic utilization of glucose carbons to fuel biosynthesis, which represents a targetable metabolic liability.
IMMU-49. BETA-ADRENERGIC BLOCKADE LICENSES THE USE OF IMMUNOTHERAPY IN PRIMARY AND METASTATIC BRAIN TUMORS
Authors: Selena Lorrey, Lucas Wachsmuth, Jessica Waibl Polania, Alexandra Hoyt-Miggelbrink, Corey Neff, Mackenzie Price, John Finlay, Xiuyu Cui, Daniel Wilkinson, Emily Lerner, Ethan Srinivasan, Kelly Hotchkiss, Quinn Ostrom, Peter Fecci
Journal: Neuro-Oncology (2023)

Abstract Immunotherapy is less effective against intracranial metastases compared to extracranial metastases and ineffective against primary brain tumors such as glioblastoma. Brain tumors present a unique challenge to in the context of immunotherapy, as these patients are immunosuppressed not just locally at the tumor, but also outside the CNS. Importantly, systemic immunosuppression observed in brain tumor patients limits the capacity of the immune system to respond to immunotherapy. Through this work we present a novel axis of immunosuppression in patients with intracranial tumors and demonstrate that overactive adrenergic signaling is a major barrier to immunotherapeutic success.Our data indicate that combining beta-adrenergic blockade with immunotherapy provides a survival benefit in the setting of brain tumors, where immunotherapy alone has proven ineffective. We demonstrate that this survival benefit is driven by a remodeling of the tumor microenvironment with an increase in cDC1s and CD8+ T cells, as well as an increase in CD40-CD40L signaling, suggesting the immune system is poised to respond. Further, we demonstrate that beta-adrenergic blockade can overcome systemic immunosuppression to restore the capacity of T cells to respond to an immune stimulus. Further, using the SEER-Medicaid database, we retrospectively examined outcomes in patients with melanoma and lung adenocarcinoma brain metastasis who received checkpoint blockade therapy alone vs those concurrently receiving beta-blocker therapy. We found that patients receiving combination therapy showed increased overall survival compared to those receiving checkpoint blockade alone. We then validated these findings in preclinical models of glioma, demonstrating that combining immunotherapy and propranolol, a widely-prescribed FDA-approved beta-blocker, extended survival. Moving forward, we suggest that combination therapy with beta-blocker and immunotherapy, particularly checkpoint blockade, represents a promising translational treatment platform for patients with primary or metastatic intracranial malignancies.
DDDR-01. P38-MAPK INHIBITOR REVERSED CISPLATIN RESISTANCE IN NON-SMALL CELL LUNG CANCER BRAIN METASTASES BY REGULATING P-GP AND BCRP OF BLOOD-TUMOR BARRIER
Authors: Lun Liang, Min Yu, Shilun Yang, Hao Duan, Zhenqiang He, Zhenning Wang, Junlei Chang, Yonggao Mou
Journal: Neuro-Oncology (2023)

Abstract BACKGROUND Previous studies have shown that the blood-brain barrier (BBB) of brain metastases (BMs) is destroyed, and the neovascularization and tumor cells constitute the blood-tumor barrier (BTB). Whether the BTB plays a role in the chemotherapy resistance of BMs is lacking in-depth research. This study aims to elucidate the possible role of BTB in cisplatin resistance of BMs from non-small cell lung cancer (NSCLC). METHODS AND MATERIALS; A multicenter retrospective cohort study including 1177 patients with NSCLC-BMs was conducted to explore the prognosis. Immunohistochemistry and immunofluorescence staining were used to verify the expression of some BBB markers in the BTB. Animal models of BMs were constructed by cardiac injection of A549. NSCLC-BMs cell lines A549-mBrain were selected in vivo. Cisplatin susceptibility tests and CCK8 proliferation tests were performed on A549-mBrain. RNA sequencing, Western Blot and qPCR were used to explore the mechanism that might regulate cisplatin resistance in A549-mBrain. RESULTS Platinum-based chemotherapy did not improve the overall survival time of NSCLC-BMs. BTB in NSCLC-BMs lacked astrocytes and pericytes, but still expressed several molecular markers of BBB, such as tight junction, transcytosis, and efflux pump. The efflux pump P-gp and BCRP expressions were higher in NSCLC-BMs than those in the lung primary lesion by immunohistochemistry in patients' tumor section. The A549-mBrain showed cisplatin resistance compared with the parental A549. Besides, the expression of P-gp and BCRP were also higher in A549-mBrain than parental A549 by Western Blot and qPCR. In A549-mBrain, inhibition of the p38-MAPK signaling pathway decreased the expression of P-gp and BCRP, thus increasing the sensitivity to cisplatin. CONCLUSION BTB may retain some BBB function in NSCLC-BMs, in which efflux pump P-gp and BCRP expression were related to cisplatin resistance. p38-MAPK inhibitor reversed cisplatin resistance in NSCLC-BMs by regulating P-gp and BCRP.
MODL-14. IMAGING, HISTOLOGICAL AND MOLECULAR CHARACTERIZATION AND COMPARISON OF POST-ABLATION RECURRENT TUMOR WITH THE PRIMARY TUMOR IN A PRECLINICAL GLIOBLASTOMA MODEL
Authors: Tavarekere Nagaraja, Indrani Datta, Natalia Morosini, Seamus Bartlett, Bhargav Ayloo, Glauber Cabral, Faith Avritt, Laura Hasselbach, Parveen Parasar, Ana deCarvalho, Jaspreet Singh, Robert Knight, Stephen Brown, James Ewing, Houtan Noushmehr, Ian Lee
Journal: Neuro-Oncology (2023)

Abstract Recurrent glioblastoma (rGBM) is highly aggressive and invasive. A reliable preclinical model that recapitulates these features is not presently available. The objective was to generate a preclinical rGBM model, characterize and compare its imaging, histological and molecular signatures in comparison to the primary tumor. Immune-suppressed, RNU/RNU female rats were implanted with U251N tumor cells in one brain hemisphere (n=33). Tumor progression in all rats was followed by longitudinal dynamic contrast enhanced-magnetic resonance imaging (DCE-MRI). In 24 rats the tumor was ablated under diffusion-weighted imaging (DWI)-guided laser interstitial thermal therapy (LITT) at post-implantation 2-weeks. Cohorts from twenty ablated rats were euthanized at post-LITT 24 h, 2- and 4-weeks and, along with 5 unablated controls, used for hematoxylin and eosin (H&amp;E) and Ki67 staining. Tissues from 4 other unablated and 4 recurrent tumors at post-LITT 2-weeks were used for RNAseq. All the rats survived the LITT procedure. Unablated controls showed increased tumor burden by post-implantation 2 weeks and were euthanized. In the LITT group, MRI showed little tumor tissue at 24 h, evidence of recurrence at 2 weeks and significant tumor tissue at 4 weeks and matched with histological evidence for tumor recurrence. Compared to the primary tumor, H&amp;E staining showed increased vascular hyperplasia, mitotic bodies and hypoxic regions with pseudopalisading necrosis in the recurrent tumor. Increased KI67 staining in recurrent tumors suggested higher rates of proliferation and evidence of infiltration into host tissue. Pathway analyses demonstrated differentially expressed genes in the canonical pathways of hypoxia-inducible factor-alpha (HIF-1α), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and OX40 signaling. The genes for the following functions were significantly affected: cell cycle, cellular movement and cell morphology. Reliable preclinical rGBM models are few. These data suggest that this model replicates the features of human rGBM and can be useful in testing putative anti-glioma therapies.
MODL-11. EXPLORING THE THERAPEUTIC POTENTIAL OF YAP-TEAD INHIBITORS FOR TARGETING GBM CELL MIGRATION AT THE INFILTRATIVE MARGIN
Authors: Thenzing Silva Hurtado, Balagopal Pai, Susana Isabel Ramos, Dolores Hambardzumyan, Raymund Yong, Nadejda Tsankova
Journal: Neuro-Oncology (2023)

Abstract Glioblastoma (GBM) is an aggressive brain tumor with a median overall survival of only 12-15 months. Despite remarkable cellular and molecular heterogeneity, all GBM subtypes exhibit an infiltrating growth pattern which leads to incomplete surgical resection and inevitable recurrence, representing a major obstacle for effective treatment and an unmet need for therapy. Our research project aims to investigate the efficacy of YAP-TEAD inhibitors, including Verteporfin (VP), on migratory properties of GBM cells at the interface between the tumor core and the infiltrative tumor margin. Recently, several groups have implicated Hippo pathway YAP-TEAD activation in GBM growth and mesenchymal transition, and our laboratory demonstrated anti-migration and anti-invasion efficacy of the YAP-TEAD inhibitor VP across GBM subtypes, in patient-derived cell and xenograft (PDX) mouse models. Here we set to develop an ex vivo model for high-throughput testing of various YAP-TEAD inhibitors using organotypic slice cultures obtained from PDX and primary glioblastoma resection specimens, focusing on tumor areas around the infiltrative margin. Tumor cells within 250µ-thick organotypic slices were infected with GFP labeled retrovirus and subjected to confocal time-lapse imaging 72-96 hours later. Slices were treated first with vehicle (DMSO) for 4 hours, and subsequently with the YAP-TEAD inhibitor VP for 4 hours. To assess drug impact on tumor cell migration, we gathered imaging data on migration properties such as speed and directionality. Analysis of a PDX model generated from a de-novo GBM surgical resection (G-17969) revealed significantly decreased distance traveled in GFP+ cells treated with VP, compared to DMSO (p-value = 0.0002, n=50 cells). These pilot results corroborate other studies demonstrating anti-invasion properties of VP, contributing towards our goal of establishing a preclinical pipeline for rapid, high-throughput screening of anti-invasion drug inhibitors ex vivo. Key words: Glioblastoma, cell migration, YAP-TEAD inhibitors, time-lapse imaging
MODL-29. EXPLORING CELL STATE TRANSITIONS IN GLIOBLASTOMA WITH LIVE REPORTING OF CELL STATES USING CRISPR/CAS9
Authors: Rebecka Stockgard, Irem Yildirim, Sean Kleindienst, Josephine Heinold, Sven Nelander
Journal: Neuro-Oncology (2023)

Abstract Glioblastoma (GBM) is the most common malignant primary brain tumor, with a median survival time of 12-15 months. The heterogeneity of GBM, ranging from inter-patient to intra-tumoral, poses a significant challenge in identifying effective treatments. At the single-cell level, GBMs comprise a multiplicity of transcriptional cell states that can change over time and in response to therapy. To explore how cell state plasticity shapes tumor progression, new experimental tools to monitor cell state dynamics in real-time will be important, if not essential. Here, we describe a live reporting of GBM cell states that utilize CRISPR/Cas9 and fluorescent proteins for tracking individual glioblastoma patient-derived cells’ (GBM-PDC) physiological gene expression, and cell state transitions over time and during treatment. The method aims to provide real-time reporting of accurate transcriptional phenotypes (e.g. OPC/NPC-like, Mesenchymal, Astrocyte states) over extended periods or in relevant in vitro or in vivo contexts. Our protocols achieved successful endogenous tagging of a common stem cell marker with full-length mCherry in up to 15 % of GBM-PDC (an order of magnitude more effective than previous reports). Real-time imaging (Incucyte S3 and IMX-C) allows us to trace individual cells’ states over time and during treatment, supported by ICC, qPCR, and Western blot, providing a reliable approach. Our next objective is to employ this method to tag several cell-state marker genes with fluorescent proteins. We can directly follow gene expression and cellular state transitions when several state-selective genes are fused with different fluorescent proteins. We anticipate establishing a robust framework to investigate the temporal plasticity and invasion patterns within GBM cells across different patients which may open for new therapeutic opportunities.
RBIO-04. INHIBITING THE SHH PATHWAY AND PARP1 IN COMBINATION ENHANCES THE RADIATION SENSITIVITY OF PEDIATRIC SONIC HEDGEHOG MEDULLOBLASTOMA
Authors: Laura Price, Bonnie Lau
Journal: Neuro-Oncology (2023)

Abstract Medulloblastoma accounts for 20-25% of all pediatric brain tumors. These patients undergo craniospinal and focal radiation therapy during their treatment, resulting in negative long-term consequences such as bone and tissue hypoplasia and decreased neurocognitive functioning. One of the most concerning effects is the significantly increased risk for secondary radiation induced cancers later in life. Thus, there is a critical need for novel approaches to radiation therapy that can effectively target and kill tumor cells while minimizing long lasting toxic effects. Here, we investigate a novel approach to radiation therapy that relies on the combination of two classes of therapeutic agents, Sonic Hedgehog (SHH) inhibitors and Poly (ADP-ribose) Polymerase (PARP) inhibitors. The SHH pathway plays a key role in medulloblastoma tumorigenesis and affects the radiation sensitivity of various cancer types such as basal cell carcinoma. The PARP family, specifically PARP1, plays a key role in DNA damage repair and affects the radiation sensitivity of pediatric brain cancers such as high-grade glioma and medulloblastoma. We hypothesize that combining these approaches by inhibiting Smo and Gli1 in the SHH pathway, and PARP1 simultaneously, will enhance medulloblastoma tumor cell killing following radiation therapy. We found that in vitro treatment with Sonidegib, GANT61, and Veliparib alone and in combination with was sufficient to significantly decrease tumor cell viability and self-renewal as measured by clonogenic survival assays (p &amp;lt; 0.01). 24 hours following these targeted treatments, 2 Gy of radiation was administered which resulted in a greater degree of decreased cell viability and self-renewal (p &amp;lt; 0.01), as well as in increased cell death. Together, this data suggests that inhibition of Smo, Gli1, and PARP1 either alone as single agents, or in combination is a promising therapeutic strategy for increasing the radiation sensitivity of pediatric SHH medulloblastoma.
CTNI-60. TREATMENT OF RECURRENT GLIOBLASTOMA WITH APG-157 VIA EXPANDED ACCESS: PRELIMINARY RESULTS FROM SIX PATIENTS FROM A SINGLE-CENTER STUDY
Authors: Ekokobe Fonkem, Colton Betts, Eva Bradshaw, Adam Tamini, Elizabeth Anyanda, Parag Mehta
Journal: Neuro-Oncology (2023)

Abstract INTRODUCTION Glioblastoma (GBM) is the most common primary central nervous system malignancy. There is poor long-term survival with a median survival of two years and little consensus on second line therapies after progression. APG-157 is a new class of botanical drugs developed under FDA’s Botanical Drugs Guidance. The purpose of this study is to assess the safety and effect of APG-157 on the six-month survival and quality of life (QoL) of patients with recurrent GBM. METHODS Approval was obtained from the Baylor Scott and White IRB (# 022-230, Approval number 58100462000) and under group expanded access protocol (IND 162339). Major inclusion criteria include histologically proven GBM and unequivocal tumor progression 12 weeks after completion of standard first-line therapy. APG-157 was administered either as monotherapy or in combination with temozolomide or tumor-treating fields. Adverse events were assessed at each study visit. Patient data were collected from study conception through April 25, 2023. RESULTS A total of 6 patients (3 male, 3 females) were treated (median age was 54). A median of 2 treatment cycles were administered. 2 Patients withdrew from the study voluntarily, 2 patients expired while on treatment, and 2 patients continued treatment at the time of data analysis. 47.4% (9/19) of the questionnaire time points were completed, however, we saw low QoL (EORTC-QLQ-C30 and EORTC-QLQ-BN20) with a mean global health status score of 4.5. No patient saw a significant increase in their symptoms and one patient reported a 6-point decrease in their neurological symptoms. One patient who was on monotherapy of APG-157 for two months showed stable disease by MRI evaluation. There were no reported adverse events from the study medication. CONCLUSION Future follow-up and a larger sample size are necessary to confirm the impact of APG-157 on six-month survival and QoL.
STEM-20. REGULATION OF GLIOMA STEM CELL MAINTENANCE AND THERAPEUTIC RESISTANCE BY EGFR MISSENSE MUTATIONS
Authors: Sidney Weaver, Aunay Miller, Mylan Blomquist, James McNamara, Keely Orndorff, Jean Kloss, Christopher Sereduk, Joseph Loftus, Shwetal Mehta, Nhan Tran
Journal: Neuro-Oncology (2023)

Abstract Glioblastoma (GBM) tumors contain a subpopulation of glioma stem cells (GSC) which can escape therapeutic effects through self-renewal and invasion. Epidermal growth factor receptor (EGFR) mutations are the most common alteration in GBM. EGFRvIII (deletion of exons 2-7) is observed in GBM (20-25%) resulting in a constitutively activated EGFR receptor. In addition, extracellular domain missense point mutations, (e.g. G598V, A289V, R108K) are observed in GBM (14.4%). These missense mutations in the EGFR extracellular domain also induces a highly active receptor by enhancing ligand binding. Earlier reports have shown that these EGFR missense point mutations have exhibited therapeutic resistance; however, the molecular mechanism of these missense point mutations in GBM remains unknown. Previous studies in our lab showed that EGFRvIII promotes GSC maintenance and therapeutic resistance via oligodendrocyte transcription factor 2 (OLIG2) signaling. OLIG2 is universally expressed in glioma and essential for reprogramming GBM cells into stem-like tumor cells. Increased OLIG2 expression promotes invasion, growth, proliferation, and survival. Here we report an increase in OLIG2 protein expression in GSCs harboring EGFR-G598V or EGFR-A289V mutations, suggesting these mutations may support stemness properties in GBM tumors. GSC expressing these point mutations display increased self-renewal, growth, and survival. In addition, EGFR-G598V and EGFR-A289V trigger distinct downstream signaling pathways in GSCs to regulate OLIG2 function. Hence, we hypothesize that GBM tumors harboring EGFR missense mutations (G598V, A289V) influence stem cell properties via multiple pathways to evade therapeutic effects and inhibiting these different signaling pathways will decrease therapeutic resistance in GBM. Understanding the mechanism of these EGFR mutations may lead to improved therapeutic strategies for GBM patients.
CTNI-81. REAL-WORLD TREATMENT RESULTS OF RELAPSED PRIMARY CENTRAL NERVOUS SYSTEM LYMPHOMA TREATED BY MEDICAL THERAPIES
Authors: Motoo Nagane, Nobuyoshi Sasaki, Yuki Yamagaishi, Kuniaki Saito, Keiichi Kobayashi, Hirofumi Nakatomi
Journal: Neuro-Oncology (2023)

Abstract Recurrence of primary central nervous system lymphoma (PCNSL) is a condition which often leads to morbidity and mortality. Consensus regarding the optimal treatment regimen for relapsed PCNSL has not been achieved due to the rarity of the disease. In this study, we conducted a retrospective, single-institution study to investigate real world treatment results of relapsed PCNSL treated by several medical therapeutic regimens. Relapsed PCNSL patients treated at the authors’ institution were identified, and progression-free survival (PFS), overall survival (OS) were analyzed among patients treated by medical therapies. Patients treated by radiotherapy, treated for intraocular or systemic relapses, or best supportive care, were excluded from the survival analysis. 83 patients with first, 44 with second, 25 with third relapse were identified. Upon each relapse, number of patients who received medical therapies for CNS lesions, radiotherapy, treatment for intraocular or systemic relapse, and best supportive care were 48 (57.8%), 5(6%), 4(4.8%), 26(31.3%) (first relapse), 31(70.5%), 3(6.8%), 1(2.3%), 9(20.5%) (second relapse), 13(52.0%), 0, 1(4%), 11(44.0%) (third relapse), respectively. A total of 101 CNS relapses were treated by medical therapies, and PFS (months), OS (months) of the four groups of treatments (rituximab, methotrexate, procarbazine and vincristine [R-MPV], methotrexate [MTX], tirabrutinib, and others) were as follows. PFS: 13.0, 4.5, 2.7, 3.0, and OS: 70.0, 26.4, 51.2, 9.7 (all relapse). PFS: 12.7, 7.0, 3.0, 3.2, and OS: 58.9, 33.1, not reached(n/r), 16.1 (first relapse). PFS: 34.3, 3.9, 25.3, 1.5, and OS: n/r, 28.1, 25.5, 7.5 (second relapse). PFS: 10.1, 3.9, 2.4, 2.9, and OS: 14.9, 22.3, n/r, 8.1 (third relapse). In relapsed PCNSL, favorable PFS was observed in patients treated by R-MPV. Favorable OS was also observed in tirabrutinib, which might suggest that tirabrutinib failure were effectively salvaged by R-MPV. R-MPV might confer better prognosis in relapsed PCNSL.